According to the official episode description, Cam (Eric Stonestreet) and Mitchell (Jesse Tyler Ferguson) think they overhear Lily insulting her new pal, and have to take a "quick look in the mirror" before they teach her a lesson about acceptance.

"This is Jackson Millarker," she wrote. "He's 8 years old, from Atlanta, and just happens to be transgender. He plays Lily's friend Tom in this week's Modern Family and he's wonderful. One of the many reasons I love being part of this show."